This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
Alpha-thalassemia is a blood disorder that reduces the body’s production of hemoglobin. Affected people have anemia, which can cause pale skin, weakness, fatigue, and more serious complications. Two types of alpha-thalassemia can cause health problems: the more severe type is known as Hb Bart syndrome; the milder form is called HbH disease. Hb Bart syndrome may be characterized by hydrops fetalis; severe anemia; hepatosplenomegaly; heart defects; and abnormalities of the urinary system or genitalia. Most babies with this condition are stillborn or die soon after birth. HbH disease may cause mild to moderate anemia; hepatosplenomegaly; jaundice; or bone changes. Alpha-thalassemia typically results from deletions involving the HBA1 and HBA2 genes. The inheritance is complex, and can be read about here. No treatment is effective for Hb Bart syndrome. For HbH disease, occasional red blood cell transfusions may be needed.
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